Choke for guns



W42 w. F. MATHls 2,306,176

cHoKE FOR GUNS Filed May 16, 1940 J8 l0 l5 I6 Il F 6 ZI /ZI 10 I9 25 V'Vz'ZLW l? l Mams INVENTOR ATTORNEYS Patented Dee. 22, 1942 S Re? 2 Claims.

This invention relates to chokes for guns and has for an object to provide a choke tube adapted to be quickly attached or detached in the field without the use of tools to adapt the gun for long and short range shooting conditions.

A further object is to provide a gun choke having a retaining sleeve adapted to be screwed onto the muzzle of the gun barrel and to receive interchangeably any one of a plurality of choke tubes.

A further object is to provide a gun choke having a combined front sight and lockingr device for preventing any of the parts becoming detached or loosened.

A further object is to provide a device of this character which will be formed of a few strong simple and durable parts, which will be inexpensive to manufacture, and which will not easily get out of order.

With the above and other objects in view the invention consists of certain novel details of construction and combinations of parts hereinafter fully described and claimed, it being understood that various modifications may be resorted to within the scope of the appended claims without departing from the Spirit or sacrificing any of the advantages of the invention.

In the accompanying drawing forming a part of this specification:

Figure l is a side elevation of the muzzle portion of a gun barrel having a choke tube constructed in accordance with the invention applied thereto.

Figure 2 is a plan view of a gun muzzle showing a modified form of gun choke comprising a retaining sleeve and a choke tube therein.

Figure 3 is a front elevation of the gun choke shown in Figure 2.

Figure 4 is a longitudinal sectional view of another modified form of the gun choke comprising a retaining sleeve and a retaining ring, the later being adapted to be threaded onto the gun muzzle to conceal the threads when the gun choke is not in use.

Figure 5 is a cross sectional View taken on the line 5-5 of Figure 2 showing the lock means for preventing accidental unscrewing of the gun choke.

Figure 6 is a detail perspective View of the sliding member of the locking means.

Figure 7 is a detail sectional view showing the joint between the muzzle and the choke tube of Figures 2 and 4.

Referring now to the drawing in which like characters of reference designate similar parts in the various views, I0 designates the muzzle portion of a shotgun barrel. In carrying out the invention a choke tube H is provided, the choke tube being formed at the rear end of the bore with a conical surface I2, disposed at an angle of about 15 degrees to the axis of the tube, which forms a compression chamber, and which merges at the front end into an elongated cylindrical surface I3 of the bore, and at the rear end merges into a beveled surface I4. The beveled surface I 4 merges into a threaded cylindrical surface I5 adapted to be screwed onto external screw threads I6 formed on the gun muzzle. The wall of the rear end of the choke tube is uniformly thickened and is provided externally with a knurled surface Il to facilitate the choke tube being easily screwed onto and of of the gun barrel without the use of tools.

When the choke tube is screwed up tight on the gun muzzle, the beveled surface lli is tightly engaged against a beveled surface i8 formed on the end of the gun muzzle to permit the pellets and gases of the shot column, or shot string, to pass smoothly over the joint formed by the beveled surface I4 and the beveled surface I8 and into the compression chamber I 2. The gases and shot pellets are compressed axially in the compression chamber and pass in this condition through the cylindrical bore I3, which is of smaller diameter than the bore of the gun, to adapt the gun to long range shooting conditions.

'I'he choke tube is held in applied position by a combined front sight and locking means which is identical for al1 forms of the invention. This includes a base I9 which is of elongated rectangular contour and is provided with an inclined top surface 20 at the rear end. A member 2| is slidably mounted on the base and is provided at the rear end with anlextension 22 which is disposed above and in advance of the inclined surface of the base and forms a front sight. The member 2I is provided at the front end with a downwardly extending linger 23 having a beveled front end 24, best shown in Figure 2, adapted to ride circumferentially along the rear edge of the enlarged end of the choke tube and lodge in a notch 25 formed in the rear edge to prevent accidental unscrevving of the choke tube from the gun muzzle.

The linger 23 is yieldably held in the notch 25 by a helical spring 26 which is mounted in a recess 21 formed longitudinally in the base I9. The operator may force the sliding member 2| against the pressure of the spring to dislodge the finger 23 from the notch 25 and permit the choke tube to be detached from the gun muzzle without the use of tools. The sliding member 2| is limited in its sliding by a transversely disposed pin 28 which is engaged through the base member and engaged in a transverse slot 29 formed in a base flange 39 which is integral with the sliding member and which is slidably engaged in a longitudinal slot 3l formed in the base I9, as best shown in Figure 5. Above the flange the sliding member is provided with a narrow neck 32 which engages the confronting faces of flanges 33 on the base i9 formed by a narrow slot cut longitudinally through the top face of the base onto the slot 3i.

A modified form of the gun choke is shown in Figure 2 in which the gun choke comprises a retaining sleeve 34 having an enlarged thickened rear end 35 provided with screw threads 36 to screw onto similar screw threads 31 formed on the gun muzzle 38. The outer end of the retaining sleeve is provided with an annular flange 39, which extends radially in the bore of the tube and is adapted to interchangeably retain any selected one of a plurality of choke tubes ll, of different choke diameters, in the retaining sleeve.

The bore of each choke tube i0 i5 tapered as shown at lil, from end to end of the tube, to uniformly compress the gases and pellets of the shot string toward the axis of the tube. The rear end of the tube is formed with a beveled surface 42 which engages a beveled surface i3 formed on the end of the gun muzzle, as shown in detail in Figure 7, These beveled surfaces are tightly forced together by pressure of the annular flange 39 of the retaining sleeve on the outer end of the choke tube when the retaining sleeve is screwed onto the gun barrel.

In this form of the invention the retaining sleeve is locked in applied position by the above described combined front sight and locking means and like reference numerals are used in this figure for the sake of clearness.

A modified form of the invention is shown in Figure 4, which is similar to Figure 2 in all rel.

spects, and has accordingly been given like reference numerals, with the exception of the retaining sleeve lill. In this form of the invention the retaining sleeve is provided at the outer end with external screw threads l5 of the same diameter as the threads 3l on the muzzle 38, and is devoid of the retaining flange 39. In lieu of this flange a retaining ring 136 is provided, having internal screw threads 41 adapted to screw onto the screw threads .i5 of the retaining sleeve. provided on its inner periphery with a radially extending retaining flange 48 which is adapted to engage the front end of the choke tube 40 and hold the choke tube tightly engaged against the The ring is :a:

gun muzzle 38. The advantage of this retaining ring is that when the retaining sleeve 44 and choke tube l0 have been removed from the gun muzzle, the ring may be screwed onto the screw threads 3'! of the gun muzzle and conceal these threads.

From the above description it is thought that the construction and operation of the invention will be fully understood without further explanation.

What is claimed is:

l. The combination with the muzzle of a shot gun terminating in a beveled surface and having external screw threads above the surface, of a choke tube terminating at the rear end in a beveled surface seated on the beveled surface of the muzzle, a sleeve having internal screw threads at one end engaging the external screw threads of the muzzle and telescopically receiving the choke tube, said sleeve having external screw threads at its other end, an internally threaded ring interchangeably received on the screw threads of the muzzle or the external screw threads of the sleeve having an annular flange adapted to engage the front end of a choke tube and clamp the choke tube against the muzzle, and releasable means disposed on the muzzle in rear of the screw threads thereof forming a front sight and adapted to prevent backing olf of the sleeve from the muzzle.

2. The combination with the muzzle of a shot gun having external screw threads, of a choke tube having a compression chamber and having a notch in rear of the compression chamber, said tube being threadedly engaged with the screw threads of the muzzle, and a combined front sight and locking means holding the tube in applied position including a base of elongated rectangular contour provided with an inclined top surface at the rear end and a transverse slot and secured to the muzzle, a member slidably mounted on the base provided at the rear end with an extension disposed above and in advance of the inclined surface of the .base and forming a front sight, said slidably mounted member being provided at the front end with a downwardly extending finger having a beveled front end adapted to ride circumferentially along the rear edge of the choke tube and seat in said notch to prevent accidental unscrewing of the choke tube from the gun muzzle, there being a recess formed longitudinally in the base, a helical spring in the recess engaging the finger to releasably hold the linger in the notch, and a transversely disposed pin carried by the sliding member engaged in the transverse slot in the base and limiting sliding movement of the sliding member to operative or to released position.

WILLIAM F. MATHIS. 

